Kopar grants a guarantee against material and manufacturing defects for twelve (12) months from the date of commissioning, however not more than eighteen (18) months from the date of the dispatch. The normal wearing is not included in the guarantee.
After the dried copper concentrate has gone through the roasting and smelting processes, it goes into a converter where "matte" is converted into metallic copper. This batch process is carried out in a horizontal, brisck-lined, cylindrical reactor called the Peirce-Smith Converter.
Converting process basically consists of four main steps: charging with "matte", blowing with air, skimming off slag and dumping the blister copper, which is approximately 98.5% pure copper.
Kopar delivered a 13'x34' Peirce Smith Converter to Boliden Harjavalta smelter in 2007. This converter is supplied with dished heads and welded riding rings, made of special steel.